If it's helpful, I have my layout set so that in the bottom of every post on my reading page I can open the link in my normal style, a light background style which sticks to browser defaults and in the users own style, I did this as while I don't have a migraine problem, it can be occasionally problemativ and/or I could be in a low light mode.

I keep meaning to write up a how-to on doing this but it needs a bit of willingness to go into S2 at the moment-if you want a walkthrough to set up something similar, let me know and I'll write one or just point you in the right direction, it's a fairly easy thing to do for most layouts.